Coil support for annealing furnace



c. J. RUBRECHT EI'AL 3,100,634 COIL SUPPORT FOR ANNEALING FURNACE Aug. 13, 1963 2 Sheets-Sheet 1 Filed Sept. 25, 1960 INVEN TOR. Charles J. Rubrechf Albert J. Minnoffe BY .ZZZ

their ATTORNEY 1.963 c. J. RUBRECHT ETAL 3,100,634

COIL SUPPORT FOR ANNEALING FURNACE 2 Sheets-Sheet 2 Filed Sept. 25, 1960 IN VEN TOR. Charles J. Rubrechf Albert J. Minnofle their ATTORNEY invention relates to a .coiljsupport for annealing furnaces and, more panticularly, toa charge support and a, s tack of coils of strip steel while being annealed in a rectangular or bell type furnace, such furnace being .well knownand commonly used in the steel industry. n

outstanding disadvantage arisingfroni the use of conventional base. structures and diffusers in .coil annealing furnaces hasbeen that due to the very heavy loads imposed by the stack pr coils and the high temperatures encountered, there is a great tendency for the base or coil supports to collapse or, at least, to become warped or distorted, thus throwing other partsout of alignment or properrelationship. e

We have ,foundthat :this difliculty may be traced to the lack of a properly constructed base or coil support and diffuser assembly.

An object of our invention, therefore, is to provide a novel coil support and diffuser assembly for supporting coils inanannealing furnace in a manner so asLto obviate the above named shortcomings and disadvantages of coil supports heretofore used. I A more specific object of our invention is to provide a novel coilsupport and diffuser for annealing furnaces, which support is mechanically constructed in a manner so as to provide amazingly higher strength and reinforcement than prior supports, while being no heavier, and which will withstand loads far in excess of loads withstood by prior structures, also which will have no tendency to distort, warp or collapse as a result of heavy loading or abnormally high temperatures or thermal shock stresses.

Other objects and advantages will become more apparent from a study of the following description taken with the accompanying drawings wherein:

FIG. 1- is a fragmentary portion, shown in vertical cross-section, of the lower part f a bell type of coil annealing furnace, which furnace is well known in art; r

FIG. 2 is an enlarged, top or plan view of the base .or charge support and diffuser, shown in FIG. 1 and embodying the present invention, showing a portion of n d States Patent 0 diffusing structure useful for thepurpose of supporting "ice .2. between, as well known in the art. Internally fired radiant tubes 1a heat the gas.

Numeral ,5 denotes a motor which drivesan air circulatingfan 6, the blades of which are adapted to force air radially outwardly so as to draw air downwardly from the central space or circular opening within the coils 3, i then through the coil support and diffuser assembly, de-

tionship, a plurality of ribs 9 of thick steel, which ribs are of involute form, extending along curves which are generally radial and having inner ends which pointgenerally to the center of bottomplate 7a. The peripheries of the bot-tom ends of ribs 9 are welded to the bottom plate, 7a to form anintegral structure therewith. Spaced from the radially inward ends of ribs 9 there are provided, on thetop surfaces or ends of the ribs 9, notches or grooves disposed in a circular path and in which is supported an inner metal ring 10, which extends only throughout the height of the top portion of ribs 9, as shown more clearly in FIG. 3. Ribs 9, for example, may havea thickness of about 2 inches and a height of about 6- inches, or any other height, whereas the inner ring 10 has a thickness of about linch but a height of only about 1 inch. Inner ring .10 may be welded to the top, notched out portions of ribs 9 so as to form an integral structure therewith. Welds are also preferably provided between the radially outward ends of ribs 9 and the outer ring 18a, such welds being made along the top of the end portions of ribs 9 which join the outer ring, also the weld may be made along the vertically extending joints between ribs 9 and the outer ring 18a. Instead of welding as described above welds may be made only between the central port-ions of the ribs and bottom plate 7a to allow free expansion of both ends of the ribs.

The cover plate 8 is of somewhat smaller diameter than the outer ring 18a to provide an air space therebetween for the flow of air drawn into the spaces. between the ribs 9, as shown more clearly in FIG. 2. A circular opening 8a is made in the central part of the cover plate as shown in FIG. 1, to serveas supporting ledges, the

the cover plate broken away for the. purposes of clarity of illustration; r

, FIG. 3 is a ventical,"cross-sectional view taken along line III-III of FIG. 2; r

FIG. 4 is a fragmentary, vertical cross-sectional view taken through bathe plate719 of FIG. 2;,

FIG. 5 is a view similar to FIG. 4 showing a portion of the baffle plate spaced from that illustrated in FIG;.J4; FIG. 6 is a fragmentary, cross sectional view showing aportion of the rib 9 which h-as a lifting hole 21; and,

FIG. 7 is a fragmentary, top or plan view ofa modified form of the base or coilsupport and diffuser showing straightradial ribs instead of curved ones.

Referring more particularly to FIG; 1 oft-he drawing,

L numeral 1 denotes a heating hood or furnace bell having a closed top portion (not shown); and an opened bottom portion, and numeral 2 denotes a bell type mufile which encloses a stack ofcoils 3 of strip' steel, supported on end, and which coils are separated by separators or. spacers 4 for the purpose of providing gas passages there-t top-surfaces of which are substantially in the same plane asthe top of outer'ring 1 8a. Radially extending grooves or slots 8b are. formed or burned into the cover plate 8, as shown, along spaced peripheral portions.

I In operation, asthe fan blades 6 are rotated so as to suck air downwardly from the center of the stack of coils 3 tofbe annealed, the air will ,fiow into an opening 13 formed in cover plate 12 and will flow through the inlet opening 14- of a pipe 15 ;which leads radially outwardly to a vertical pipe 16 to conduct air or heated gas to the space between the ribs 9. The bottom of. pipe 16. is

closed b y a cap: 161:, Air which is thrown out by centri- "fugal force byfblade 6 will move radially outwardly and will beldeflec-ted upwardly by baffles 19, as shown in, FIGS. 4' and 5, and will flow through the; space between c the outer periphery of top plate 8a and the outer ring -1=8a. rAtmosphere' outlet openings 17 are. provided; in the bottom plate '7. Openings 21 are provided in certain of the ribs for facilitating lifting of the base as-f sembly. 0penings 20a and 20b are for the purpose of inserting thermocouples or other instruments. The remaining parts of the base are substantially the same as described above in connection with FIGS. 1-6.

' same asfin FIGS. 1-6. Therefore, we have provided a ficient and an amazingly strong supporter base' and Top plate 8, in some instances, may be omitted from the structure shown in FIGS. 1-7.

By omitting both the top plate 8 and the bottom plate 7a, the structure described in FIGS. 1-7 may also be used either as a base or as separators to take the place of separators 4, shown in FIG. 1, in which case, of course, the diameter of the outer ring Will be made .s mvalleras Well as that of the inner ring.

Both the curved ribs of FIG. 2 and the straight ribs of FIG. 7 also provide greater uniformity of distribution and circulation of heatedair.

Thus-it Will be seen that we have provided an e ffi cie nt' base and diffuser that solves the problem of distortion, I i

warping andcollapsing that has plagued the art. I FIG. 7 shows a modification7a of the support having straight radial ribs 9a, instead of curved ones, the inner end portions ofdyvhich arejoined together by inner ring 10a in the manner as described above for ribs 9* and ring 10. The remaining parts of the base are substantially the highly, reliable, ef-

" porting the soils to be ann diffuser for supportingta stack of coils to be annealed in q a bell-type or rectangular furnace, which base diffuser assembly is reinforced insuch manner as to avoid any possibil ty of warping or distortion or collapsing of the generally radially-extending ribs separating thettop and bottom plates of the base, despite abnormally high 7 p and enormous loads provided by the annealing coils, or high temperatures encountered, or stresse s resulting from loading ornon-uniforrnityof temperatures. 7

' While We have illustrated and described several embodiments of our invention, it will be understood that these are by Way of illustration only, and that various changes andmodifications may be made Within the con-,

, p v 3 5,: templation of our invention and within the scope of the following claims.

We claim: 7

1. A support and difiuser for supporting coils to be annealed in a bell-typefurnaoe, comprising a. base plate having a central opening adapted to accommodate a fan portion, a plunality f substantiallyuadially extending, spaced metal ribs supported. on and weldedto said base plate, the inner end portions of said ribs haying transversely extending slots fprmed onlyir'i theupper surface portions of said ribs-said slots defining a circular path,

a metal ring supported in said, slots and integrally elded to the top end portions or. said ribsso as to new ribs togethenjithe top surface? of-s'aid ringbeing flu the-top 's'urfaces of 'said'ri bjs, anouter, outer ends of said ribs, "an o'pjplateof ameter thanfsjaid, outer said ribs and said in ed a est s E a central opening, whereby an spaceiifs provided tweenthe'perirneter ot said t p pla l andth'ei'inne face of said outer ririgitoal'lb fair lloWi rigibetvv ribs to'communica'tewith the sp; ceexteriorbf the-outdr periphery of said coilsi 2. A support'anddiffu ser"as-recited in radially extending, peripherally spacedslots aretormed only, in the outer peripheral portionof said top plate} I References Cited inthe file 'thi s patent" j I 1UN1 ED TAT P T N S 1 k with 

1. A SUPPORT AND DIFFUSER FOR SUPPORTING COILS TO BE ANNEALED IN A BELL-TYPE FURNACE, COMPRISING A BASE PLATE HAVING A CENTRAL OPENING ADAPTED TO ACCOMMODATE A FAN PORTION, A PLURALITY OF SUBSTANTIALLY RADIALLY EXTENDING, SPACED METAL RIBS SUPPORTED ON AND WELDED TO SAID BASE PLATE, THE INNER END PORTIONS OF SAID RIBS HAVING TRANSVERSELY EXTENDING SLOTS FORMED ONLY IN THE UPPER SURFACE PORTIONS OF SAID RIBS, SAID SLOTS DEFINING A CIRCULAR PATH, A METAL RING SUPPORTED IN SAID SLOTS AND INTEGRALLY WELDED TO THE TOP END PORTIONS OF SAID RIBS SO AS TO TIE THE RIBS TOGETHER, THE TOP SURFACE OF SAID RING BEING FLUSH WITH THE TOP SURFACES OF SAID RIBS, AN OUTER RING ENGAGING THE OUTER ENDS OF SAID RIBS, AND A TOP PLATE OF SMALLER DIAMETER THAN SAID OUTER RING AND DIRECTLY SUPPORTED ON SAID RIBS AND SAID INNER RING TO FORM A PLATFORM FOR SUPPORTING THE COILS TO BE ANNEALED, SAID TOP PLATE HAVING A CENTRAL OPENING, WHEREBY AN AIR SPACE IS PROVIDED BETWEEN THE PERIMETER OF SAID TOP PLATE AND THE INNER SURFACE OF SAID OUTER RING TO ALLOW AIR FLOWING BETWEEN SAID RIBS TO COMMUNICATE WITH THE SPACE EXTERIOR OF THE OUTER PERIPHERY OF SAID COILS. 